{- Multiply all the numbers in a `List` Examples: ``` ./product ([+2, +3, +5] : List Natural) = +30 ./product ([] : List Natural) = +1 ``` -} let product : List Natural → Natural = λ(xs : List Natural) → List/fold Natural xs Natural (λ(l : Natural) → λ(r : Natural) → l * r) +1 in product